Prevalence of EGFR Mutations and Clinico-Pathological Characteristics of Chilean Lung Cancer Patients

Background: Lung cancer (LC) is the second leading cause of cancer death in Chile, causing >3,000 deaths everyyear. Epidemiological LC data in Chile is scarce and scattered. Here, we aimed to quantify the prevalence of EpidermalGrowth Factor Receptor (EGFR) gene mutations in a Chilean cancer center. These data may identify individuals thatcould benefit from targeted therapies such as Tyrosine Kinase Inhibitors (TKIs). Methods: A total of 1,405 Biopsiesfrom 1,381 LC patients were retrospectively analyzed retrieving clinical data from EGFR mutants including age,gender, histological type, smoking habits and type of EGFR mutation. We also analyzed overall survival (OS) rates.Results: From all patients 21.7% had clinically relevant EGFR mutations, and a median age at diagnosis of 65 years.Most were female (64%), classified as adenocarcinomas (94.5%), and non-smokers/light smokers (93.1%). The mostprevalent mutation was exon-19 deletions (50.6%) followed by Leucine-to Arginine 858; OS was 15 months. Clinicalfollow-up information was available for 83 patients. The use of TKIs in these patients significantly improved OS.Conclusion: The prevalence of EGFR mutations in the studied population was 21.7%, comparable to other countriesin Latin America. The most frequent EGFR mutation was exon-19 deletion, OS in this group was 15 months, and TKIssignificantly improved OS.